In fiscal year 2000, the United States Postal Service delivered approximately 208 billion pieces of mail. The average daily volume of mail delivered during fiscal year 2000 was 500 million pieces.
At present, the process of delivering the mail is a relatively complicated one. That process can be broken down into two components: (a) transportation and (b) distribution. The term “transportation” as used herein is intended to refer to the nodes and routes, which define the flow of mail (or other objects) between plants/processing facilities (or other sorting points). Transportation includes the inter-plant transportation network and the plant to delivery unit networks. (A delivery unit is a post office, station or branch that has mail delivery functions to the point of final delivery for a mail item.) It does not include activity within the plants themselves.
The term “distribution” as used herein refers to the combination of equipment, processes and plants that sort mail (or other objects). Distribution generally takes place between the point at which originating mail is picked up from its point of origin and the point at which it reaches its point of final delivery. The distribution of mail is assisted by the use of five and preferably nine digit ZIP codes, which refer to defined geographic areas.
It must also be noted that mail items come in varying shapes. Examples of current mail shapes include flat-size, letter-size, parcels, and outsides. Currently, plants process more or less all shapes of mail. However, because mail-processing equipment is generally shape-specific; i.e., can only process one shape of mail item, it is inefficient to locate in each plant every type of processing equipment. Nevertheless, currently, transportation of mail is organized according to mail class, rather than according to mail shape.
A need continually exists to improve and further optimize the transportation and distribution process where a large number of objects must be processed, including particularly in one example a large number of mail objects. Such improvement should rely, among other things, on the use of shape-based criteria in organizing the transportation of mail items (or the like) between plants and their distribution within plants.